Table 3.
Diagnostic accuracy of different low CrAg LFA titers in patients with different immune status
| Threshold | Value % (95% CI) | |||
|---|---|---|---|---|
| Sensitivity | Specificitya | PPV | NPV | |
| Serum | ||||
| = 1:10 | 39.6 (29.7–50.1) | 100.0 (69.2–100.0) | 100.0 (90.7–100.0) | 14.7 (7.3–25.4) |
| With predisposing factors | 33.3 (16.5–54.0) | 100.0 (54.1–100.0) | 100.0 (66.4–100.0) | 25.0 (9.8–46.7) |
| Without predisposing factors | 42.0 (30.2–54.5) | 100.0 (39.8–100.0) | 100.0 (88.1–100.0) | 9.1 (2.5–21.7) |
| ≥ 1:5 | 72.9 (62.9–81.5) | 70.0 (34.8–93.3) | 95.9 (88.5–99.1) | 21.2 (9.0–38.9) |
| With predisposing factors | 70.4 (49.8–86.2) | 66.7 (22.2–95.7) | 90.5 (69.6–98.8) | 33.3 (9.9–65.1) |
| Without predisposing factors | 73.9 (61.9–83.7) | 75.0 (19.4–99.4) | 98.1 (89.7–100.0) | 14.3 (3.0–36.3) |
| CSF | ||||
| = 1:10 | 50.0 (21.1–78.9) | / | 100.0 (54.1–100.0) | 0.0 (0.0–45.9) |
| With predisposing factors | 33.3 (4.3–77.7) | / | 100.0 (15.8–100.0) | 0.0 (0.0–60.2) |
| Without predisposing factors | 66.7 (22.3–95.7) | / | 100.0 (39.8–100.0) | 0.0 (0.0–84.2) |
| ≥ 1:5 | 66.7 (34.9–90.1) | / | 100.0 (63.1–100.0) | 0.0 (0.0–60.2) |
| With predisposing factors | 50.0 (11.8–88.2) | / | 100.0 (29.2–100.0) | 0.0 (0.0–70.8) |
| Without predisposing factors | 83.3 (35.9–99.6) | / | 100.0 (47.8–100.0) | 0.0 (0.0–97.5) |
Data are presented as % (95% confidence interval)
Abbreviations: CI confidence interval; NPV negative predictive value; PPV positive predictive value; LFA lateral flow assay; CrAg cryptococcal antigen; CSF cerebrospinal fluid
aSpecificity was not calculated because no false positive case was found in patients with low CrAg LFA titer in CSF